Modelling Glacier Retreat after Ice Shelf Collapse

Wednesday, 17 December 2014
Jan De Rydt1, Gudmundur Hilmar Gudmundsson1, Helmut Rott2 and Jonathan L Bamber3, (1)NERC British Antarctic Survey, Cambridge, CB3, United Kingdom, (2)ENVEO, Innsbruck, Austria, (3)University of Bristol, Bristol, BS8, United Kingdom
Satellite measurements have shown the consistent and ongoing speed-up and retreat of glaciers that were once buttressed by the collapsed Larsen B ice shelf. Understanding the response of grounded ice to ice shelf collapse is a prerequisite to future predictions of sea level rise as other ice shelfs such as Scar Inlet or the Larsen Ice Shelf further weaken due to changing atmospheric and ocean conditions.
We present model results for a number of sensitivity experiments that aim to simulate the response of glaciers to the collapse of Larsen B. For this purpose we use a state of the art shallow shelf model with grounding line resolving capabilities. The model is initialized to observed pre-2002 conditions with the ice shelf in place, and transient runs are done that study the response to a weakening and removal of the ice shelf.
Results are compared to a novel dataset of observed ice velocities, which provides the most comprehensive overview of dynamical changes after the collapse to-date. In addition, we investigate glacier response to the future collapse of Scar Inlet, a remnant of the Larsen B ice shelf which has been suggested to show signs of weakening in recent years. Results will also be used to inform a future Antartic Peninsula-wide modelling study.